1. Field of the Invention
The present invention relates to recording and/or reproducing apparatus wherein a tape is wrapped on a peripheral surface of a drum and contacts at least one head for recording signals on, or reproducing signals from, the tape by scanning it.
2. Description of the Prior Art
In a helical scanning type video tape recorder (VTR) it is necessary that the magnetic tape runs stably and smoothly at all times. However, in practice there is a tendency for frictional forces between the magnetic tape and the peripheral surface to increase when the magnetic tape has been running for some time and under certain conditions. This can result in stick/slip transport of the magnetic tape with consequent pulsating motion of the magnetic tape, or even complete sticking of the magnetic tape. Any such interference with free transport of the magnetic tape has a very adverse effect on recording and reproducing, and may easily result in damage to the magnetic tape.
There have been some prior proposals for overcoming this problem, and some of these proposals have included the provision of grooves on the peripheral surface of the drum, but these proposals seem to have been based on an imperfect understanding of the reasons why the frictional forces between the magnetic tape and the peripheral surface of the drum tend to increase, and these proposals have not resulted in any satisfactory solution to the problem.